1. Field of the Invention
The present invention relates to a perpendicular magnetic recording head and a perpendicular magnetic recording/reproducing head, which records by applying a magnetic field in a direction perpendicular to the medium surface of a recording medium.
2. Description of the Related Art
A perpendicular magnetic recording head has a laminated structure in its facing surface opposite a recording medium, the laminated structure being composed by providing a return yoke layer on a main magnetic pole layer with an intermediary non-magnetic insulation layer disposed therebetween. The main magnetic pole layer and return yoke layer are magnetically connected to each other at a back position of the medium-facing surface in a height direction. In the non-magnetic insulation layer there is embedded a coil layer for applying a recording magnetic field to the main magnetic pole layer and return yoke layer. In a magnetic recording head having such a structure, a recording magnetic field is induced between the main magnetic pole layer and return yoke layer by applying electric power to the coil layer, and the recording magnetic field is perpendicularly incident from the medium-facing surface of the main magnetic pole layer to the hard film of a recording medium and returns to the return yoke layer after passing through the soft film of the recording medium. In this manner, data recording is carried out in the area of a recording medium facing to the main magnetic pole layer (see United States Patent Application Publication No. US20050083608 A1).
In addition to the above, a perpendicular magnetic recording/reproducing head has a reading portion including a lower shield layer formed on a non-magnetic insulation layer provided on a slider and an upper shield layer formed on the lower shield layer with an intermediary inorganic insulation layer (gap insulation layer) disposed therebetween, the inorganic insulation layer having a reading element therein.
A return yoke layer and shield layers of a perpendicular magnetic recording head are generally composed of a thin magnetic body film having a substantially rectangular shape, and when an external magnetic field is applied, magnetic flux in the thin magnetic body film concentrates on an edge thereof. At that time, among magnetization components, the component in a height direction becomes largest, which causes overwriting of existing data (Edge Write). That is, it is necessary to make magnetic field components in the height direction smaller to suppress the Edge Write magnetic field, the magnetic field components being generated from each edge of the return yoke layer and shield layers.